class_docstr: A currency identifier, as defined by ISO-4217.
  
  Parameters
  ----------
  code : str
      ISO-4217 code for the currency.
  
  Attributes
  ----------
  code : str
      ISO-4217 currency code for the currency, e.g., 'USD'.
  name : str
      Plain english name for the currency, e.g., 'US Dollar'.
code: def __new__(cls, code):
      try:
          return _ALL_CURRENCIES[code]
      except KeyError:
          if code is None:
              name = "NO CURRENCY"
          else:
              try:
                  name = ISO4217Currency(code).currency_name
              except ValueError:
                  raise ValueError(
                      "{!r} is not a valid currency code.".format(code)
                  )
  
          obj = _ALL_CURRENCIES[code] = super(Currency, cls).__new__(
              cls
          )
          obj._code = code
          obj._name = name
          return obj
  
file_path: zipline/zipline/currency.py
imports: from functools import total_ordering
  from iso4217 import Currency
label_desc: Use image node_id 1 for calling the Currency obj's underlying member method code with example usage: obj.__new__(cls, code) and returns: _ALL_CURRENCIES, obj